Refractory material and process for producing the same.



UUA l INH UH PLAS l IC- UNITED STATES PATENT oEEIoE.

CHARLES LADD NORTON, OF MANCHESTER, MASSACHUSETTS.

REFRACTORY MATERIAL AND PROCESS FOR PRODUCING THE SAME.

Patented July 6, 1909.

Serial N0. 457,827.

To all whom it may concern:

Be it known that 1, CHARLES LADD NOR- TON, a citizen of the UnitedStates, and resident of Manchester, in the county of Essex and State ofMassachusetts, have invented new and useful Improvements in RefractoryMaterial and Processes for Producing the Same, of which the following isa specification.

10 My invention relates to the manufacture of sheets, blocks or otherforms of heat insulating, weather resisting and electrically resistantrefractory material suitable to miscellaneous protective purposes andparticularly adapted for use as roofing or tiling in situations where awater and weather res1st1ng materlal 1s desirable.

In Letters Patent of the United States numbered 847,293, granted to meMarch 12, 1907 I have described a refractory material composed ofasbestiform fiber, and magnesium oxid hydrated by adding an appropriateamount of water to the combination, the whole compacted under heavypressure while the hydration of the oxid was in process. I

have discovered that the modification of the process described in thesaid patent by the addition of other ingredients, produces a refractorymaterial different (both in kind and degree) in its physicalcharacteristics from the refractory material described in said patent.

To roduce the new and refractory material w ich is the subject of thisspecification,

I proceed according to a method analogous to that described in my saidpatent, but employ the following ingredients in the manner ereinbelowdescribed.

I take fine short asbestos fiber or prefer- 4 ably the fibers obtainedby grinding and cleaning the ser entine rock in which asbestos in itsnormal fibrous condition is usually found in nature, and mix therewithmagnesium oxid, preferably obtained b the calcination at a dull red heatof a fine y comminuted magnesium carbonate, a precipitated magnesiumcarbonate being in m opinion the best material for this urpose by reasonof the extreme fineness 0 its comminution; I also employ in the mixturean hydraulic cement as P v d t, and if it be desired to ren er 'ngproduct extremely hard, strong and resistant to water, I add to themixture a proportion of calcined silica in the form of fine sand whichis mixed with the magnesium carbonate and roasted along with it. Thusthe two solid ingredients are on the one hand dry, clean asbestiformfiber, and on the other hand, a dry mixture of magnesium oxid andhydraulic cement either with or without an admixture of sand. As abovestated when the sand is used as an ingredient, I find it advisable tomix it with the magnesium carbonate and roast this mixture of magnesiumcarbonate and sand together. These two solid ingredients are then mixedtogether dry in proportiions sqjqstantially as (fiollowjrshof the asesti orm er 300 poun s, o e magnesium 0x13 and h'draulic cement 7 poun seacfi, and 1f sand is used, aBout 15 pounds of sand. When theseingredients are thoroughly mixed, I add thereto a weight of watersubstantially equal to the aggregate weight of the solid ingredients;the water so added 7 forms with the solid ingredients a moist pulp thesolids of which hold the water evenly distributed. Upon the formation ofthis Wet pulp it is spread upon a filter bed in an hydraulic press insuch quantity as is required for the formation of the desired sheet,plate, or other form of refractory materia land the pulp is thensubjected in the press to a ressure which preferably is between 200 anpounds to the square inch. The operation of the filter press is tosqueeze out a large roportion of the water contained in the pulp eavingtherein enough water to perorm the office of hydration or setting of thecementitious materials, namely the magne- 9 sium oxid and hydrauliccement. The pressure is applied while the process of hydration is goingforward. Sheets or other bodies of refractory material made as aforesaidare then laid in stacks to await the final setting of the cementitiousmaterials contained therein. Where the shape of the articles thus formedpermits it, I find it to be advantageous to subject them during theirsecond; a or final settin to a co rabe rs; 109 sure. is may be wellaccomplishe 0 inserting between each adjacent pair of sheets materialand this slight extrusion of water is confined to the early stages ofthe secondary compression. The compression of the material during thesecondary or final setting improves the strength, toughness and hardnessof the material while it does not appreciably alter the shape ordiminish the thickness of the slabs or sheets.

Sheets or other objects of refractory material composed and made asaforesaid are extremely hard, have a high tensile strength, are tough,free from laminations and proof against warping under any subsequentconditions and are susceptible of receiving a high polish. They may beused for roofing, tiling, fire-proofing etc. and also for purposes wherea strong heat insulating materlal is desired.

hat I claim and desire to secure by Letters Patent is:

1. The process of making refractory material which consists insubjecting a mixture of asbestiform fiber, magnesium oxid, hydrauliccement and water to ressure accompanied by the extrusion 0 surplus waterwhile the hydration of the cementitious materials is in progress.

2. The rocess of making refractory material whic consists in subjectinga mixture of asbestiform fiber, magnesium oxid, hydraulic cement and asilicious sand with water to pressure accompanied by the extrusion ofwater while the hydration of the cementitious materials is in progress.

3. The rocess of making refractory material whic h consists in roastinga mixture of magnesium carbonate and a silicious sand until thecarbonate is thoroughly calcined mixing the calcined magnesium and sandwith asbestiform fiber and hydraulic cement adding water to theaforesaid mixture of solids in quantities sufficient to form a wet pulp,and then subjecting the pulp to pressure while hydration of thecementitious materials is in progress expressing the surplus water andcompacting the entire mass.

4. Refractory material com osed of a compacted mass of uniformlyistributed asestiform fiber, magnesium oxid, and hydraulic cement.

5. Refractory material composed of asbestiform fiber, 300 parts,magnesium oxid 75 parts, hydraulic cement, 75 (parts-all byweight-uniformly distribute in a compacted mass, with an amount of waterin composition proportionate to the chemical requirements of thecementitious ingredients.

6. Refractory material com osed of a compacted mass of uniformlyistributed asestiform fiber, magnesium oXid, and 11y.- draulic cementand an amount of water in composition PIOIiOltiOIliltG to the chemicalrequirements of t 1e cementitious material.

7. Refractory material composed of a compacted mass of uniformlydistributed asestiform fiber, magnesium oxid, sand and hydraulic cement.

8. Refractory material composed of asbestiform fiber, 300 parts,magnesium oxid, 75 parts, hydraulic cement, 75 parts, sand 15 parts-allby Weight-uniformly distributed in a compacted mass with an amount ofwater in composition proportionate to the chemical requirements of thecementitious ingredients.

9. Refractory material com osed of a compacted mass of uniformlyistributed asestiform fiber, magnesium oxid, sand and hydraulic cementand an amount of water in composition proportionate to the chemicalreruirements o the cementitious material.

signed by me at Boston, Massachusetts this third day of October 1908.

CHARLES LADD NORTON.

Witnesses:

CHARLES D. WOODBERRY. ODIN ROBERTS.

